How much heat is required to melt 20 g of gold at 1064.18 °C with a heat of fusion of 64 J/g *

Answers

Answer 1

Answer:

1280J are required.

Explanation:

Heat of fusion is defined as the amount of heat required to change its state from liquid to solid at its melting point at constant pressure.

As heat of fusion of gold is 64J/g, there are required 64J to melt 1g of gold at its melting point. The energy required to melt 20g is:

20g * (64J/g) =

1280J are required


Related Questions

what is p³×p simplify ​

Answers

Answer:

The answer is p.

Explanation:

You have to apply Indices Law :

[tex] {a}^{m} \times {a}^{n} ⇒ {a}^{m + n} [/tex]

For this question :

[tex] {p}^{3} \times {p}^{1} [/tex]

[tex] = {p}^{(3 + 1)} [/tex]

[tex] = {p}^{4} [/tex]

1. The forks shown are made of silver (Ag). Some of the silver forks
shown have lost their luster—they have become tarnished. This is an
example of Type here.

Pleasee help

Answers

Answer:

Corrosion

Explanation:

Silver is known as a noble metal. Noble metals are those metals that are resistant to corrosion.

However, we can not say that silver is completely resistant to corrosion because silver can corrode when exposed to air and sulphur.

Exposure to air and  sulphur leads to the coating of the silver with a sulphide layer thereby making the metal to become tarnished and loose its metallic luster.

equation invalid?
Al +202
→ A1203
O A. An atom of aluminum (Al) is created in the reaction.
B. An atom of oxygen (O) is destroyed in the reaction.
O C. The equation violates the Law of Conservation of Mass.
O D. All of the above.
1 View Gizmo

Answers

Answer:

B. an atom of oxygen o is destroyed in the reaction

What is an advantage of using natural gas rather than a coal burning power plant?

Answers

Answer:

I hope it helps u

Explanation:

The advantages of using natural gas rather than coal are the following,

Natural gas is present in large amount than coal.Natural gas is less costly than other fossil fuel sources of energy. It increases security by decreasing dependence.Natural gas is more environmentally friendly.Natural gas is much safer to store.It is reliable.Natural gas is a fossil fuel, though the global warming emissions from its combustion are much lower than those from coal or oil.Natural gas emits 50 to 60 percent less carbon dioxide (CO2) when combusted in a new, efficient natural gas-power plant compared with emissions from a typical new coal plant.

8. When rubidium and fluorine combine to produce the compound RbF, che ions
formed have the same electron configuration as atoms of
a neon, only
b both argon and neon
c both krypton and neon
d both xenon and neon

Answers

Answer:

The answer is C, both krypton and neon.

Explanation:

I got the answer wrong and my teacher told me that c is the right answer choice

Ions can be made by single element or covalently bonded group of elements. The covalently bonded group of elements is called polyatomic ions or polyatomic atoms. Therefore, the correct option is option C.

What is Ions?

Any species that contain charge whether it is positive charge or negative charge is called ions. The example of polyatomic ions are sulfate, phosphate, nitrate etc.

Cation is the species that loose electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral, the charge over cation and anion is also called oxidation state.

Rb react as cation Rb ⁺ with electron distribution as [Kr] after removal of 1 electron from s orbital. F react as anion F⁻ with electron distribution [He] 2s² 2p⁶ which is equal to electronic configuration of neon.

Therefore, the correct option is option C.

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urgent plzz help meeee thx

Answers

Answer:

8

Explanation:

From the question given above, the following data were obtained:

t–butyl ion = (CH₃)₃C⁺

Number of valence electron =?

The valence electron(s) talks about the combining power of an element or compound as the case may be.

Considering the t–butyl ion, (CH₃)₃C⁺ we can see that it has a charge of +1 indicating that it has given out 1 electron to attain the stable octet configuration which has a valence electrons of 8. Thus, the valence electron of t–butyl ion, (CH₃)₃C⁺ is 8

Help me please in science !! ( 10 points )

Answers

Answer: Nuclear

Explanation:

Nuclear energy generates power through fission, which involves splitting uranium atoms to produce energy. The heat released by fission is used to create steam that rotates turbine to generate electricity.

The energy produced by nuclear plants is carbon free but the products formed are radioactive and hence their transportation, storage, and disposal is a big problem. It can not be dumped like normal waste.

A compound with a mass of 48.72g is found to contain 32.69g of zinc and 16.03g of sulfur. What is the percentage composition of the compound​

Answers

Answer:

dic

Explanation:

why are state symbols used in chemical equations

Answers

Answer:

state symbol meaning

[s] solid

liquid

gas

aq] aqueous dissolved in water

Explanation:

often chemical equations are written showing the state that each substance is in. the [s] sign means that the compound is a sold. the l sign means the substance is a liquid. the aq sign stands for aqueous in water and means the compound is dissolved in water

thank me later.

State symbols are used in chemical equations bc they identify what phase the substances are in.

how to find the number of atoms present in 22g of co2​

Answers

Answer:

22g of  2

C

O

2

have  3.011×1023

3.011

×

10

23

  2

C

O

2

molecules.

Explanation:

Hope this helps! ^^

Students are discussing the pros and cons of petroleum as a naturals resource. Which of the following do you agree with?

Answers

Answer:

this is a multiple choice question where are the answers

Explanation:

Two reproductive cells undergo meiosis. Each daughter cell undergoes meiosis. How many cells are produced when the daughter cells divide

Answers

Answer:

The correct answer is  - 32 cells.

Explanation:

In the meiosis type of cell cycle or cell division, a single parent cell divides into four daughter cells, unlike mitosis. Meiosis takes place in the reproductive or sex cell and called reduction division.

As we know each cell divide into four daughter cells.

1  reproductive cell = 4 daughter cells

2 reproductive cell = 8 daughter cells

Now each daughter cell undergo meiosis than each cell will produce 4 cells so,

8 daughter cells will produce:

8 *4 = 32 cells.

Thus, the correct answer is  - 32 cells.

Balance the chemical equation below using the smallest possible whole number stoichiometric coefficients.
P4(s)+NaOH(aq)+H2O(l)➪
PH3(g)+Na2HPO3(aq)

Answers

P4 + 4NaOH + 2H2O → 2PH3 + 2Na2HPO3
, not sure

A chemical equation is said to be balanced if the quantity of each type of atom in the reaction is the same on both the reactant and product sides. In a balanced chemical equation, the mass and the charge are both equal. P₄ + 4NaOH + 2H₂O → 2PH₃ + 2Na₂HPO₃.

A chemical equation is said to be balanced if the quantity of each type of atom in the reaction is the same on both the reactant and product sides. In a balanced chemical equation, the mass and the charge are both equal.

A chemical equation must balance according to the rule of conservation of mass. According to the rule, mass cannot be generated or removed during a chemical process.

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a) Find the gas speed of sulfur dioxide at 100.0 degrees Celsius? ______________

b) What is the rate of effusion of sulfur dioxide compared to nitrogen triodide at the same temperature? __________________

Answers

a. 381.27 m/s

b. the rate of effusion of sulfur dioxide = 2.5 faster than nitrogen triiodide

Further explanation

Given

T = 100 + 273 = 373 K

Required

a. the gas speedi

b. The rate of effusion comparison

Solution

a.

Average velocities of gases can be expressed as root-mean-square averages. (V rms)  

[tex]\large {\boxed {\bold {v_ {rms} = \sqrt {\dfrac {3RT} {Mm}}}}[/tex]

R = gas constant, T = temperature, Mm = molar mass of the gas particles  

From the question  

R = 8,314 J / mol K  

T = temperature  

Mm = molar mass, kg / mol  

Molar mass of Sulfur dioxide = 64 g/mol = 0.064 kg/mol

[tex]\tt v=\sqrt{\dfrac{3\times 8.314\times 373}{0.064} }\\\\v=381.27~m/s[/tex]

b. the effusion rates of two gases = the square root of the inverse of their molar masses:  

[tex]\rm \dfrac{r_1}{r_2}=\sqrt{\dfrac{M_2}{M_1} }[/tex]

M₁ = molar mass sulfur dioxide = 64

M₂ =  molar mass nitrogen triodide = 395

[tex]\tt \dfrac{r_1}{r_2}=\sqrt{\dfrac{395}{64} }=\dfrac{20}{8}=2.5[/tex]

the rate of effusion of sulfur dioxide = 2.5 faster than nitrogen triodide

When examining features on the ocean floor, like a volcano, how would it appear?

severely eroded
only somewhat eroded
not eroded at all
barely eroded compared to land volcanoes

Answers

the answer is not eroded at all.

Answer:

barely eroded compared to land volcanoes

Explanation:

the other person is wrong

A scientist named J. J. Thomson developed a model of the atom in which electrons are spread throughout a cloud of positive charge. Which discovery directly caused scientists to revise this model?

Answers

Answer:

A small mass of positive charge was discovered in the center of the atom.

Explanation:

Atoms is the combination of protons, neutrons, as well as electrons particles. The particles that are in the centre of atom is Protons and neutrons, which made up the nucleus, this nucleus is surrounded by electron.

The discovery that directly caused scientists to revise this model of the atom is that A small mass of positive charge known as proton, and a positive charge particle was discovered by Ernest Rutherford, in the center of the atom in the year 1900. Ernest Rutherford through his research resulted to splitting of the atom during nuclear reaction and proton was discovered.

describe how calcium may be used in the body​

Answers

The body needs kill game to maintain strong bones in to carry our mini important functions almost all cocky and is done and bones and teeth were supposed district you’re a heartless the valley also need to go get it for my sister move in for news to give you massage messages between the rain and every body part

In case you don't know what Calcium Is:

a silver-white divalent metal, occurring combined in limestone, chalk, gypsum, etc., occurring also in vertebrates and other animals, as a component of bone, skeletal mass, shell, etc., and as a necessary element in nerve conduction, heartbeat, muscle contraction, and many other physiological functions.

Calcium can be found:

Calcium is a soft white chemical element found in bones and teeth

answer:

Using the definition..calcium may be used in the human body by nerve conduction, heartbeat, muscle contraction, and many other physiological functions.

·.•·°.hope this helped!!!·.•·°.

What forces typically hold nonmetal atoms together within a molecule?
A. Metallic bonds
B. Covalent bonds
C lonic attractions
D Intermolecular forces

Answers

Answer:

B - Covalent bonds

Explanation:

Covalent bonds are a class of chemical bonds where valence electrons are shared between two atoms, typically two nonmetals. The formation of a covalent bond allows the nonmetals to obey the octet rule and thus become more stable.

‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️

Is this right? If not which is it pls

Answers

Answer:

i believe it is b as well

Explanation:

0.0721 moles of a compound have a mass of 31.008 grams. What is the molar mass?

(please show work and provide an explanation!)

Answers

Answer:

divide the moles by gram to get molar mass

use calculator and get yo ans

An atom of sodium can transfer its one valence electron to an atom of
O magnesium to complete the octet rule
O fluorine to complete the octet rule
O nitrogen to complete the octet rule
O calcium to complete the octet rule

Answers

Answer: O fluorine to complete the octet rule

that right

Can someone help?? This is really hard.

Answers

Answer:

See Explanation

Explanation:

Let us consider the first two reactions, the initial concentration of CO was held constant and the concentration of Hbn was doubled.

2.68 * 10^-3/1.34 * 10^-3 = 6.24 * 10^-4/3.12 * 10^-4

2^1 = 2^1

The rate of reaction is first order with respect to Hbn

Let us consider the third and fourth reactions. The concentration of Hbn is held constant and that of CO was tripled.

1.5 * 10^-3/5 * 10^-4 = 1.872 * 10^-3/6.24 * 10^-4

3^1 = 3^1

The reaction is also first order with respect to CO

b) The overall order of reaction is 1 + 1=2

c) The rate equation is;

Rate = k [CO] [Hbn]

d) 3.12 * 10^-4 = k [5 * 10^-4] [1.34 * 10^-3]

k = 3.12 * 10^-4  /[5 * 10^-4] [1.34 * 10^-3]

k = 3.12 * 10^-4/6.7 * 10^-7

k = 4.7 * 10^2 mmol-1 L s-1

e) The reaction occurs in one step because;

1) The rate law agrees with the experimental data.

2) The sum of the order of reaction of each specie in the rate law gives the overall order of reaction.

In your own words, explain why we have seasons on Earth. Why do some places have all 4 seasons and others seem to only have 1 or 2?

Answers

we have seasons on earth because of the way the earth is tilt on its axis. at a certain time in the year, the sun's rays reach certain parts of the globe more than others.

some places have 4 seasons because they are in the northern hemisphere, which is in the sweet spot of the sun's rays that give us each season. other places only have 1 or 2 because they are not in the northern hemisphere.

Is BaOH2 soluble or insoluble in water?

Answers

Answer:

Explanation:

Tough question.

The answer is very dependent on the temperature of the water. At 0o C, less than 5 grams is soluble in water.

The curve increases as the temperature increases. At 80oC about 35 grams  is soluble in water 100 mL of water.  So Ba(OH)2 is very soluble at higher temperatures.

Maybe the question can be resolved just a little better at room temperature. The solubility is still less than 5 grams / 100 mL. That makes it slightly soluble or more soluble than other things.

So to answer the question, you need to specify the temperature. I would say it is, but be prepared to defend your answer.

The Big Bang theory is used to explain the origins of the universe. Why is this called a theory and NOT a law?

Answers

Answer:

It's called a theory because it has not been proven yet. so we can not claim it to be a fact without proof.

Answer: There is no concrete evidence.

Explanation: If we could do an experiment and create the Big Bang and watch it happen and study it, it would be law. It's for the same reason that evolution is considered a theory. We are not watching it take place and there is no eye witness account of evolution happening because evolution happens over millions and millions of years. If we could sit here and watch the universe be created without need for simulations or theories, then it would be law.

What percent of a mammal’s genetic material comes from each gamete?
A.10%
B.100%
C.25%
D.50%

Answers

Answer:

D.

Explanation:

because gametes are sexual reproducing cells, like sperm and egg cells are gametes. and those make up 50% of you

To solve this we must be knowing each and every concept related to gamete. Therefore, 50% of a mammal’s genetic material comes from each gamete. The correct option is option D.

What is gamete?

Sex cells are another frequent name for gametes. The fundamental name for them is "reproductive cells," and they are a component of human reproductive system.

These gametes are indeed the ones that aid in sexual reproduction and they are charge of creating the zygote, a whole new cell that is known as a zygote. These cells are haploid cells, in which each and every gamete typically carries a unique version of the chromosomes. 50% of a mammal’s genetic material comes from each gamete.

Therefore, 50% of a mammal’s genetic material comes from each gamete. The correct option is option D.

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The rate of acceleration of an object is determined by the mass of the object and...
A) The forces acting on the object
B) The change in kinetic energy of the object
C) The initial velocity of the object
D) The direction of movement of the object

Answers

Answer:

a. forces acting on the object

As an electron in an atom moves from a higher energy state to a lower energy state, the atom
1 becomes a negative ion
2 becomes a positive ion
3 releases energy
4 absorbs energy

Answers

Answer:

3 releases energy

Explanation:

An electron in an energy level has a definite amount of energy associated with it at that level.

Electrons can undergo transitions from one level to another. However, when the electron changes its state, it must absorb or emit the exact amount of energy which will bring it from the initial to the final state.

When the electron is excited, it moves from the ground state to an excited state, it must absorb energy. On returning from an excited state to a lower level or the ground state, energy is emitted, giving rise to a line in the spectrum.

Answer: 3 because it releases energy

What is the mass of 6.25 moles of Ca(OH)2?

Answers

mass/moles x mr
so you need to work out the rfm of Ca(OH)2= 40(16+1)2= 40+34= 74
and then use the formula= moles x mr
6.25 x 74= 462.5
Answer= 462.5g

what happen when Nacl solution reacts with AgNo3solution .name the two types of reactions to which does it belong​

Answers

Explanation:

A chemical reaction where two chemical compounds exchange ions with each other is called a double displacement reaction.

Also, when an insoluble salt is formed due to chemical reaction between two chemical compounds is called a precipitation reaction.

For example, [tex]NaCl(aq) + AgNO_3(aq) \rightarrow NaNO_3(aq) + AgCl(s)[/tex]

Here, ions are exchanged between the compounds [tex]NaCl[/tex] and [tex]AgNO_3[/tex] . Also, [tex]AgCl[/tex] is the precipitate formed.

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